Fluorescent lighting



y 1950 E. G. GAYNOR ETAL 2,507,898

FLUORESCENT LIGHTING Filed Oct. 1, 1945 4 Sheets-Sheet l w 5 4 R w m M v Y N P A G a n K F\ N M F M DA mm m. mm mm QE mm mm QQ a m N mm mm m; a 2 H 2 "W aw Q. mi w l fi H Wm H m: a

0 A 2 q M I ll lum May 16, 1950 GAYNQR m- 2,507,898

FLUORESCENT LIGHTING Filed Oct. 1, 1943 4 Sheets-Sheet 2 Eowm G.GAYNOR HAROLD A am y 6, 1950 E. G. GAYNOR EI'AL 2,507,898

FLUORESCENT LIGHTING Filed Oct. 1, 1943 4 Sheets-Sheet 4 EDWIN G. GAYNOR HAROLD KA 5W5 fiatenteci May 16, 1956 "UNITED PAT 'O'IFTFIC'E 2,507,898 FLUGRESCENT LIGHTING H Edwin 13 Gaynor lgairfield, and .Har.old'. K.- .Andrews, Stratford, Conn.

ApplicationOctober 1, 1943. Serial No. 504596 19 Claims .1 This invention i elates to :new and useful movem n s i li ht app ra us. a h s paricu a l ti n t fluores ent fightin A qbi ct the inv nti is to ro i e a m a whe eb flu rescen awns ay be eas ly and,

latteribeing p ovided witha cover which maybe of anydesired appearance and/or design and of any desired material to the end that esthetie-di'f sre a ong se s ez Q 1am s.-mav;fi; l:s pression.

. Yet another object is to provide a; fluorescent i htin appara ses nd t d a d which. in addition to a thermal starter apparatus includes a the mal. relay means for .opening: the. supply lineon repeated atte ptsand vfailures on the part of the .startertwhexeby thecurrent will .not,. re-. main on in futile attempts of the startertostart an exhausted lamp.

. A further v.objectris to provide a two-part, fluorescentlamp socket asindioated and, wherein. one ofsuch parts is removable from a fixture along with the lamp and wherein the thermal, starter of thelighting system is mou t d withinsaid removable socket. part.

.- .Anadditional objectisto provide. a fluorescent.

lighting apparatus including the. lamp and the neces a y soc s, nd h r in. t e so ke s are o such construction that the lampanav be applied insure starting of the.

2 ever, it is to 'be understood that the invention is not limited to the-details-dis'closed but includes all such var-iations an'd modifications as fall within the spirit of theinvention and-the scope- 0fthe appended claims.

In the drawings? 1.is asideelevational view-ofa fixture and a fluorescent lamp the...-1atter being. mounted. by the. sockets otthe present invention;

Fig. 2.15 a bottom.lplan ,view ofthe device of Fig. l

Fig. 3 is a sideelevational.zviewiof the lamp and the detachable portions sorcplugs of the present detachable oretwo. part sockets;

Fig. 4 is. an .elevational, view showing one-side otthe plug .of one. socket;

5. is a similar view showing theotherside of said plug;

Fig. 6 is a view similar to. Fig. 4 but. showing the plug of the. other; socket;

Fig. '7 isxa .view showing the reverse. side of the plug of Fig. 6;

Fig. 8. is a .view partly in section and partlyin elevation and showing theplug and .base assemblyofthe socket atone end of a fiuozescentlamp,

the cover of-the plug beingindicated by dotted linesand the partsheing shownon'alarger scale;

Fig. 9 is asectional view taken as along the plane of the line 9.9-of- -Fig. 3;

Fig. 10 is atransverse sectional view taken as,

along the plane ofthe. line.1f0+|0.0f.E-i'g. 9.;

Fig. 11 is a similar view taken as. alongthe plane of theeline l.l..-.l1l;of Fig. 9;

.Fig. v12 is. a sectional view takenas along the plane of the line l2.-.|'2 of Figs 9;

Fig. .13 is a front elevational view ofone of= the socket bases'or base portions;

- Fig. 14 is. a bottornplanview of suchbase;

Fig. 15 is a tQppla-n view of such base the. usual qoveror closure beingaomittecl;

Fig. 16 is alongitudinai sectional view-through said base, the view being along the line iii-+1.8. of Fig. 15;

Fig. 17.15 a, transversesectionalview through said base the view beingtaken alon the plane of the line l-1 l1-ofFig. -15.;-

Ba :18 isv a m lar v ew takenaiong th plane of th line 1 8 of s .5;.

Fig. 19 is a perspective view of 0, 16. oi the contacts removed fromsaid base;

Fig.- 20 is a view similar to Fig. 8 but showing; the two part socketv at. the other end ofxsaid flucrescent lamp;

Fig-.21 is a longitudinalcent al sectional-view taken as alongthelinell zl ofJEig. '20-; and

Fig. 22 shows the wiring diagram.

Referring in detail to the drawings the invention is illustrated using a fixture of any desired style or type, herein generally designated Ill, and including a hollow elongated body having a bottom or lower wall i l. Mounted on the fixture Ill and disposed at the lower side thereof is a fluorescent lamp it. It is to be understood that the fixture it may be or the shape or design and the construction desired and that generally speaking its length is determined by the length or" the Iiuorescent lamp with which it is to be used.

Mounted on the fixture ill or otherwise convenientiy located is a switch l3 including an operating handle or manual Hi. When the fixture H3 is located in a high place or in a place inconvenient for any other reason the switch l3 will not be mounted on the fixture but will be mount-' ed in some convenient spot. In the fixture wall H are a pair of holes I5 in predetermined spaced relation and adapted for use in connection with an extension means for applying a lamp l2 to the fixture when the latter is in a high place or the like. Such an extension means or applicator is disclosed in detail in my companion application, Serial Number 503,912, filed September 2'7, 1943. This application issued March 13, 1945, as U. S. Patent No. 2,371,437.

Specifically the lamp I2 is mounted on the fixture lll by means of separable or two part sockets l6 and I1 located at the respective ends of the lamp. Socket [6 includes a base l8 and a plug l9 while socket l'l includes a base 20 and a plug 2|. The bases l8 and 2B are of identical construction but there is some difference between the plugs l9 and 2|. However, in each case the plug is, physically and electrically, readily connected with and disconnected from the base whereby the lamp [2 may be easily and quickly mounted on and removed from the fixture I0 and when mounted thereon will be electrically connected as will later appear in detail.

Lamp I2 is of standard construction and includes an elongated tubular glass body having the usual end caps 22 and 23 through which extend contact pins or tangs for insertion into engagement with contacts of sockets. Such pins or tangs are arranged in pairs and as shown pins or tangs 24 and 25 at one end of the lamp constitute a pair while the pins or tangs 26 and 27 at the other end of the body constitute the other pair. These pins or tangs are connected with filaments 28 and 29 respectively (see Fig. 22), located at the respective ends of the lamp and within the glass body of the latter.

. Since the bases I8 and 20 are of substantially identical construction but one, the base l8, will be described in detail although it is to be understood that such description applies to both bases and it is noted that the same reference characters have been applied to the parts of such bases. Base [8 includes a body 30 of insulating material. This body is open at its upper side and on its lower or under side is provided with a projecting portion or neck 3! rectangular in shape and in fact of a shape and size to enter and rather snugly fit in the opening usually provided in a fluorescent lamp fixture for the reception of a portion of a socket.

A pair of entrance slots 32 through the neck 3| communicate with chambers 33 and 34 within the body 30 and such chambers are open at their upper sides as clearly shown in Fig. 16. A wall 35 stops short of the upper edge of the insulating body 30 but serves to separate the chambers 33 .remote ends of said entrances.

and 34. About midway of the height of the body 36 the chambers 33 and 34 are laterally enlarged providing shoulders 36 and 31 (Figs. 8, 13, 15 and 16) and such chambers are also enlarged rearwardly providing shoulders 38 and 39 (Figs. 17 and 18). Thus shoulders 36 and 38 together form an L-shaped surface while shoulders 31 and 39 provide a similarly shaped surface. The foot portions of such shaped surfaces are in opposing relation.

Each of the mentioned chambers receives a contact and while these contacts are of the same construction they are arranged in opposin relation and are given separate reference numbers in the assembly drawings. Thus in chamber 33 there is located contact 40 while in chamber 34 there is mounted contact 4|. Each such contact (see Fig. 19) includes a mounting portion or plate 42 of generally L-shape from the inner edge of an arm portion of which depends an arm 43 bent upon itself at 44 providing a portion 45 extending upwardly at an angle. The upper portion 46 of such arm is again bent and extends back at an angle as toward but with its free edge above the plate 42. Attention is directed to the fact that portion 46 is at a shaper angle than portion 45 and the purpose of this will be set forth.

When located in the respective chambers 33 and 34 the contacts 40 and 4| have their plate portions 42 disposed on the L-shaped surfaces provided by the shoulders 36 and 38 and 31 and 39 respectively. The arm portions of the contacts then extend downwardly so that their bight portions 44 are disposed on shoulders 41 immediately inwardly of the entrances 32 and at the Thus (see Fig. 16) the arm portions 45 and 46 of the respective contacts extend partly across the entrance slots 32 of the respective chambers. Screws 48 may pass through contact plate portions 42 and be threaded into sockets provided for them in the body and in addition binder post screws 49 are provided on the respective contact adjacent to recesses or notches 50 provided in the upper free edge of the body for the entrance of lead wires 5| and 52 thereto.

The contacts 40 and 4| or at least the arms thereof comprising the portions 45 and 45 are of spring metal. The wall 35 in its opposite sides in alignment with such spring arms is provided with grooves or slots 53 and 54 aligned with the entrance slots 32 and into which contact prongs may partly enter and by which such prongs may be partly guided as will appear. The portion of wall 35 comprising the inner end of the slot or groove 54, is about midway its ends and at a point substantially opposite where the arm of the contact bends to provide the portions 45 and 46, provided or formed with a horizontal shoulder 55. This shoulder enters into the locking together of the bases and plugs of the respective two part sockets as will be made clear. Binding post screws 49 are shown as threaded into nuts 56 (see Figs. 17 and 18) disposed in suitably shaped pockets opening through the L-shaped surfaces above mentioned.

' The bases I8 and .20 are rigidly mounted in the fixture H]. To this end the latter is provided adjacent its respective ends (or in such spaced relation as is determined by the length of the lamp to be used) with a pair of openings or holes 51 and 58 of a size and shape to receive the neck portions 3| of the base bodies 30. As above suggested these holes are of a standard size in fixtures now in use and thus the bases 18 and 20 amassemay-be mountedon existing fixtures without dif- "SS -an'da bGIt BI *passes through such registering oraligfiingholes in the matter o'feach of the bases. Qn'the upper side of each base is an insulatin plate M resting on the upper edge of the WaQ-llAtE arid on'such plateis a-m'etal plate 63.

Bolts 6! *pass through both such plates and threaded-onto such boltsare nuts 64. Thus it will be' se'en that'on tightening'of nuts 64 on'bolts BI -the bases are secured to the fixture l and as the re'ctangular neck portions 3| of such bases ar'e' hel'd in similarl-yshaped holes in the lower wall-of fixture IB the bases are firmly mounted and h ld againsttur'n'ing or other movement rela'ti've to the fix'ture.

When the basesare inounted 'on the fixture as described the plugs l9 and2l are simply applied to the "lamp' li! and the latter mounted by connecting the plugswith the-bases. This requires butta 'simple-rectilinear movement of the lamp and the plugs. Referring now to the plug l9 shown inl igs. 4,'5,1i8,9, 1G, 11 and 12 as well asinFigsflj Z and 3,it is noted that'the same includes a-housingcomprising a mounting body 65""anda'cover '66. Mounting body 6-5 is of insulasting material or the parts mounted on such body- 'must"be insulated"therefrom and cover 66 since it' isnot' engaged by any of the contact parts may be 'of insulating'material'or of metal as may be de'sired in anysparticular case for the purpose of ornamentation or the like.

'secu'red to the upperend'portion of body 65 as by rivets 61 are a pair "of contacts or prongs 6 8sand 6'9 projecting beyond the upper end of the phig 19" for' insertion through the entrance slots 32 o'f -ba"se l3: and:intoiengagementwith the contaots M andal respectively of such base. Preferab'ly bo'dy EE is provided'with elongated recesses receiving portionsrof .the prongs whereby the latter- 'earei'lield against turning movement although other tmeanymay be used "for that purpose. As here shown the rivets-61' are hollow and are internally "tapped for 'the threading thereto of screws fl used forsecuring the cover 66 to the bo'dy 65. "Ifdesiredacover 36 may have. counterbores ll'receiving'the heads of said screws.

-Body' fifi mounts a pair of contacts 12 and I3 in spaced 'relation'tothe'prongs' 68 and 69 and these-fcontacts are shown as tubular rivets passing through the body. The contacts are for the purpose"-ofireceivingxthe contact pins or tangs 24 and25' at oneend of the lamp [2 and are shown" as sodoing in Figs; 8 and 12. A'screw I4 securesa'lcontact member IE-to the inner side df 'b'ody fiia'nd suchfiv member in addition 'tothe portion held against the :body by said screw includes -anoutwardly-and upwardly extending free spring larm 75. Contact 513 is electrically connected'withmember 75 by a wire 11.

A bimetallic thermalelement 18 has an arm H -located under a lateral extension 80 of the prong fill and an upwardly-and outwardlyicurving- 'ortionsthefreeaend 8| .ofnwhich is bent upon 'itselfiproviding =a1zhook+like portion. "When the lamp =is in use the free end "portiono'f the 'arin 1" is located under the hook 'like portion of the' bimetallic element 18 as showmby the full linesin Fig. 9. 'Thus it will* be understood lthat wire =11 completes a circuit between rivet 1-3 andmember 1'5 and that the circuit fromthe latter to the prong 6 9 is completed by the I bimetallic element 18 whenithe latter isengaged-withithe free end IE-or" member-1 5 as inFig. 9.

From the conta'ot Jzavvire 82 '(shown as insulated) connects with a bent metal post 83 mounte'd by the bodyJGS. Wire 82 may:be electrically connected with post 83 but..p'referably is merely supported by said post and includes an exposed portion bent into acoilM extending betweempost S3 and a somewhat similar p'ost fixedtoand in electrical contact with-'pron 68. withrthis arrangement. itlwill ib'e seeni'that .contact :12 fmay be electrically connected" with prong :68 :through wire-i.82,'coil 84 andspost 853although thez'actual connection :as here'shown is throughthe.-'named parts and also the posit-83.

Theposts 83 and 85' havetheirupper ends :bent to extend toward one another-andthussupport the coil 84 in spaced 'relationto the-body -li5'but also within :the curved .portion'iof' thetbimetallic element 18. This coil 84 is a heating .coil1iand on :the happenin ofrfcertainthingsias will appear) is adapted to'influence the'bimetallic'element iflito havethelatterashiftand release the free end portion 'lfizofuthe member '15 whereuponi'such end :portion springs outwardlyaas to the dotted line-position of Fig.9.

A' button 8iiaoperates through: an -openingprovidedin the front wall'of cover:66 .and at the inner side :of said cover is provided with. a:fiange 81 whereby the button may not be moved outwardly entirely through thementioned' opening. At its inner end the button 86'bears against the arm-or portion-l6 ofthe'member '15. Thus in the v.event the bimetallic element has become heatedland released'ithe said-arm orportion-l6 so-that-sthe latter :hasmoved to the dotted line position of Fig. 9- it willibecle'ar that when-such element has cooled: and returned "to normal: position the free endof arm 16 may be forced'inwardly by the-:b'utton.86 --and-=will:cam the-element out of the w'ayonsnap past the hooked portion of the-element to :the underside thereof to beagain held-by' saidelement in electricalengagement therewith.

.Fig. -8 shows thetprongs of-yplug "9 engaged with thecontacts 40 and '4 I'of the base-l'8. There it is noted that these :prongssare notchedin their outer edges-as at"88 towardwtheir free ends and thatthe.bentffreenarm. portions of the contacts enter such-notches. :As the arm portions-45 are at the angle shown nbestin- Fig. 16 theprongs may be easilyforced throughthe entrances 32 and'pastthecontactxarms to-the positions shown in Fig. 8. llowever,- owing to' the different and more pronounced inclination; of the portions 46 of thezcontact' arms withdrawal of-the prongs from the base is resisted to a greater extent than is-ctheinsertion of 'suchgprongs. This isof some assistance in maintaining the plug 19 in connectedrrelation with the base 18.

Additionally it"isnoted that :the opposed edges of"? the {prongs are i provided :with shoulders 89. In'the'present case the shoulder 89" on prong 68 is notaused. The spring --ar-m-of contact-40 is stronger, in that :it is heavier or'--; of greater temper;v or thelike, than the corresponding arm of .contact M Thus as the; prongs ware inserted 7 into tlie'base the. spring arm; of :contact 40.:tends amasse- 7 the prongs and the entire plug I9 toward the contact 4| bringing the shoulder 89 of prong 69 over the shoulder 55 on the dividing wall 35 of the base body. This provides a simple positive lock means preventing casual movement, of the plug I9 from the base I8.

However, on a slight lateral movement of the plug in the opposite direction the Spring arm of contact 49 is overcome and the shoulder 89 of prong 69 moved from over the shoulder 55 whereupon the plug may be withdrawn from the base subject only to frictional resistance as will be offered by the engagement of the spring contact arms with the prongs and particularly the resistance of the inclined arm portions 46 to movement of the prongs.

Plug 2| is quite similar to plug I9 and includes a body 99 of insulating material and a cover 9I which may or may not be of insulating material as desired. A pair of hollow rivets 92 (similar to the hollow rivets 61 of plug I9) secure a pair of the prongs 99 and 89 to the body 99 and are tapped for the reception of screws 94 which as in the case of the screws 19 may be insulated from the cover if the latter is not of insulating material and which serve to secure the cover to the body.

In addition a pair of contacts 95 and 96 comprising hollow rivets are mounted by the body and in fact pass therethrough for the reception of the contact pins or tangs 26 and 21 respectively of the lamp I2. A wire 91 connects contact 96 with a heater coil 98. A screw 99 secures a bimetallic thermal element I99 comprising a contact member to the body 99 and a wire I9I connects such element with the contact 95. Element I99 includes a free movable end portion I92 carrying a contact I93.

A second bimetallic contact element I94 has an arm I95 disposed beneath and anchored by and in electrical contact with the lateral extension 89 of the prong 69. Element I94 is substantially U-shaped and includes an outer arm I96 carrying a contact I91 normally engaged by the contact :93 whereby a circuit is normally closed between contact 95 and prong 69 by wire I95, element I99, and element I94.

The heater coil 98 is located in the bight portion of the bimetallic element I94 and is sup ported at its respective ends by posts I99 and I98 the former of which is supported by body 99 while the latter is supported by and in electrical contact with prong 68. These posts have their upper ends bent toward one another providing support for the coil and the latter through wire M, and the posts I91 and I98 completes a circuit from contact 96 to prong 68. The particular relation and function of the elements I92 and I94 Will later be given in detail but here it is noted that on heating up coil 98 will influence element I94 and the latter will tend to open or its arm I96 will tend to move away from arm I92 of element I99 thereby separating the contacts I93 and I91.

The action of the spring arm of the contact 49 on the prong 99 when the plug 2| is connected with the base 29 as in Figs. 20 and 21 will it is believed be clear. However, it is pointed out that such contact arm will tend to shift the prong 99 and thus the entire plug 2I laterally to dispose the shoulder 89 of such mentioned prong over the shoulder 55 on the dividing wall 35 of the base body whereby to prevent rectilinear movement of the plug away from the base, in effect providin a positive lock between the plug and base as in the case of the plug I9 and its base I8.

It is believed that an understanding of the circuit shown in Fig. 22 will help in the reading of of an explanation of the operation and advantages or" the device the structure of which has heretofore been set forth in detail. Referring now particularly to the wiring diagram (Fig. 22) the parts therein have been given the same reference identifications as in the other figures of the drawing. However, some additional parts are shown in the wiring diagram.

A wire I I5 has been added to complete the circuit from bimetallic element I8 to prong 69 of the plug I9 and a similar wire I l9 has been added to complete the circuit from element I94 oi the plug 2I to the prong 69 of such plug. Thus the wires 5 I5 and I I9 are used in the diagram to show the connections actually made by the clamping of the mentioned bimetallic elements under the lateral extensions 89 of the prongs 69 of the respective plugs. Additionally a three element condenser III is shown as connected across the post I88 and the added wire H9 with the intermediate element of said condenser grounded. This is to prevent radio broadcasting by the lamp I2 as will later be again mentioned.

On closing of switch I3 to start the lamp the circuit may be through wire I I2 to wire 52, contact 49 of plug I9, prong 69, wire H5, element l3, member '15, wire TI, contact 13, contact pin or tank filament 28, contact pin or tank 24, contact eyelet 12, wire (or post) 82, heater coil 84, wire (or post) 85, prong 68, contact M of plug 59 and wire 5I to contact 49 of base 22, prong 99 of plug 2|, wire II9, element I94, element I99, wire I9I, contact eyelet 95, contact pin or tang 2T, filament 29, contact pin or tang 26, contact eyelet 95, wire 91, heater coil 99, wire or post H38, prong 68 of plug 2|, contact M of base 22 and return wire II3 having therein any or the usual ballast H4.

The circuit being as described the filaments 29 and 29 will be heated and will heat the contents of the lamp tube to form a conductive vapor. After a predetermined time interval the heater coil 98 causes the bimetallic element I94 to move the contact I91 out of engagement with contact I93 thus opening the line circuit. Now

if the lamp has been sufiiciently heated the cur-' rent will flow from filament 28 across the lamp to filament 29 and through wire 91, coil 98, prong 69 of plug 29, contact 4| of base 29, return wire H3 and ballast II4. Under these circumstances elements 15 and 18 remain in contact and the circuit to filament 28 is through them. On opening of switch I3 the lamp is extinguished.

The element I92 and I94 together with the heater coil 98 and associated parts constitute a starter. Filaments 28 and 29 must be heated to a glow for a sufiicient time before the running voltage is impressed on the lamp to obtain lighting. Present devices used for the purpose of controlling the time of glow of the filaments do not function to give a reasonably immediate light when the lamp is cold, as in a temperature of 40 degrees F. or less. The glow is not maintained for a sufficient length of time. The devices used are thermal relays comprising a source of heat, a fixed contact and a piece of bimetallic thermostatic metal carrying a contact.

The socket I! has the present starter mounted therein and the latter includes a thermal relay which glows the filaments for a relatively long time to favor lighting of the lamp at low ambient temperature. The presentthermal relay includes the, addedpiece .of;.relatively stiff metal H12 carnying the contact! 03. Lost motion between member 102 andthev thermal element I04 accounts for..a-.delay in the operation of the relay to the end that-theglow of the filaments 23 and 29 is maintained for a IQI er. time.

Member. I82 isof stiifer metal to smooth out thejerkiness of the. thermor-metal. in the relay. This smoothness makes for superior operation of .thevcontacts-which are prone .to are and weld if opened and closed in a jerky manner. This addedstiffermember 102. is ofbimetal but only fon theepurpose of keeping its relative position both. to the element. I M- and its contact constant despiteyarying. ambient temperatures. During operationor the .lampthe present thermal relay is;. .-held openv by-- the running current of thelamp (throu hcoil- 98.) rather than byby-passed current. as with the devicesheretofore in use.

Glowing-of the filaments-prior to lightingv of thedarnp: takesacomparatively large current. The. current. to-thelamp is throttled by-the impedanceorballast I l landthe latter becomes hot it-calledmpon to supply, for. more than a short tin1 e,-. electricity in addition'to' that required to keep .the-.-lamp lighted: The life span of the lamp is reached. when the filament looses its electrifyingpowen- Then theautomatic starter above describedrand. thoseat .present in use will make the, filamentsglow but the.- lamp. will not light wl'iereupon.- as the .starter heats up and then cools offiitzwill make the filaments glow and glow again in an effort to start the lamp. These repeated iattempts "to start -antexhausted lamp result in=aeconsiderab1e awasteof electricity inadditionitmw-hichthe ballasts heats up and a firehazard gdevelops.

The present. invention includesmeans: to control-the successive. attempts otthestarter to star the lamp. Such-means comprises the. memberhlfi the bimetallic. element 18, the heater coil 8fi. and .the associated. parts. This means is mountedinr-plug iS-ot-socket 16.. Such means accumulates heat 1 from the,.-successive. attempts to start -a .lamp. with an inert (deactivated) filament .tothe end that element 18 shifts from-the full line to the dotted positiQn of FigVQ and the free endportion l6---of.,member 'lfi moves from underandout of contact withthe-said element permanently opening the circuit to cut the: supply line tofhelectricity... Itispreferredthat the parts be. constructed and. arrangedto permit of. the starter. mekingseve-ral. attempts to start a lamp. The time. of movementof. element 18 to open. circuit.pesitiomdenendson theolosenessof its relat-ion toheatercoil M, .the thieknessof the eler ment, etc.

Attention. is. directedto. the. fact that the thermal. bimetallic.v element 18 .is .both a switching memberw andalatchingmember. When the lamp iszremoved from the fixture l .for replacement thesocket plug l9iisremovedalong-with thelamp. Then whenanewlampis .provided the said plug inconvenient to, the. party making the.change of lamps. I-Ie. presses-,. the ..button.- 86,. forcing. the arm J6'of. member 15 inwardly to. again snap into 1-.v.c s ition;under. the hook-likeportiontl of. the bimetallic, element which. the meantime has cooled ofi landreturned. tonormal condition .and

.nosi n- The present. invention provides means whereby a'dampf may. be. easily. changed- The fluorescent lamn islefiicientlyloperative .for. about2000 hours. C'ha i inalamps every 100.. to 290 days. and. tem;

porary removal. between times for cleaning is a serious matter in plant economy. The handling of the lamp, aglass tube from three to six feet in length, at places. 15 to 20 feet above a floor cluttered with machinery, show cases, and the like is an awkward and hazardous job. The job is made extra difiicult owing to the necessity for fitting the extremely small contact pins or tangs attheends of the lamp into equally small slots or recesses in-fixed sockets built into fixtures.

The present. invention includes the mounting of thelamp by aepair of two part sockets. The plugs are attached tothe lamp by placing them against. theends of the lamp with the contact pins or tangsof. the latter in the contact eyelets of the plugs. Thereis a. rather snug fit of the contact pins or. tangs in the contact eyelets. Followingmounting of the plugs on the ends of thelamp the latterismounted'on the fixture substantially by a rectilinear .movement involving inserting the prongs of. the plugs through the entrances 32 .of the bases intoengagement with the contacts 40 and M within such-bases.

A slight lateral movement of the lamp and plugs takes placeafter. the prongs are. in the basesto hook the shoulders 89. of the prongs 59 over the shoulders 55 on. thedividing walls-of the bases. This provides a positive lockso that there is no danger of the lamp casually droppingfrom the fixture or beingjarred' from theslatter- A positive lateral movement tocarry the shoulders 89 from over the shoulders 55. is required before the prongs may be withdrawn from the bases. An important feature is the firm connection between the contact eyelets of the sockets and the pins or tangs of the lamp.

The fluorescent lamp found ready acceptance in weaving and other. textile plants. Its low external temperature allowed it to beput into desirable locations denied to the hot incandescent lamp. However, the fixed sockets involved ex.- posed live conductors to. the ambient lint. and created afire hazard. In locales where the atmosphere is gas'laden short circuiting and increased maintenance cost occurs. The present sockets include holes rather than slots for the reception of the pins or tangs of the lamp and thus there are no exposed parts as the pins or tangs have rather snug fitsin the eyelet type contacts. Such a .construction would be impractical if not impossible with fixed socket constructions as.heret'ofore used.

The sockets heretofore used for mounting of fluorescent lamps were rigidly mounted in the fixtures. The design of such sockets was fixed. Esthetic difference among lamp designers cannot .be .met in a fixed designmade primarily for utilitarianpurposes, In the present socket the part exposed tothe eye is merely a cover. It has nopart inthe functioning of the socket and accordingly may be made in various shapes. of various materialsand in desired colors, etc.

The usual starter for. a fiuorescentlamp is a fragile ..device.- attached to thelamp-fixture by some means especially provided for that purpose. The starter isnot usually accessableand when the starter is .to be replaced the lamp. must first be removed. In the present-case the starter is in one .of-thesockets .andin the part ofsuch socket removable with the lamp. Thus the present starteris easilyaccessable- Further the present starterlis of ahardyconstruction and. otheavier wire so.thatitcarries the operatingcurrent of they lamp and. has-indefinite life. The time required for. opening-of the present starter maybe I l varied by having the element IM closer to or farther from the heater coil 98 and by varying the thickness of the metal of the parts etc. As the starter is within the plug of a lamp socket no extra part for the mounting of the starter is required.

In the constructions heretofore in use neither the lamp nor the starter can be removed by extension means. The complicated engagement of the small terminal pins or tangs of the fluorescent lamp with the equally small channels in the fixed sockets is a safe matter only when the hands are actually grasping the lamp. In the present construction the lamp may be applied or mounted by extension such as that shown in my companion application above mentioned and in addition the lamp together with the plugs of the respective sockets may be removed from the fixture by extension means since only 9, slight lateral movement is needed after which a straight outward pull separates the parts.

As the fluorescent lamp sets up static it has been proposed to include small two element condensers in the starter. The effectiveness of such constructions is very limited. In the present instance the three element condenser I II is mounted in one of the bases and the third element of such condenser is grounded as to the fixture ID or the attaching bolt Bl contacting such fixture. This is an effective means for suppressing radio interference by the lamp l2.

Having thus set forth the nature of our invention, what we claim is:

1. In a fluorescent lamp socket. a base and plug separable from said base, contacts in said base, said base having entrances to said contacts and a shoulder therein and at one side of and facing away from one of said entrances, said plug having openings to receive the contact pins at one end of a fluorescent lamp, prongs on said plug and insertable through said entrances into engagement with the contacts of the base, means for electrically connecting said prongs with lamp contact pins inserted through said openings, one of said prongs having an outwardly facing shoulder, and spring means in said base at the side of the entrance opposite said shoulder for moving said plug and. base relatively on insertion of the prongs of the former into the latter to dispose the prong carried shoulder over the first mentioned shoulder and thereby provide means to prevent casual separation of the plug from the base.

2. The combination as in claim 1 wherein said spring means comprises one of the contacts in said base.

3. A fluorescent lamp socket comprising a base and a plug separable from said base, contacts in said base and entrances leading to said contacts, prongs on said plug and insertable through said entrances into engagement with said contacts, a pair of contacts on said plug portion. for detachable engagement with the contact pins on the end of a fluorescent lamp, means mounted on said plug including a heater coil connecting one of said pair of contacts with one of said prongs, and means within said plug and including a thermally operable starter switch located to be influenced by said heater coil and electrically connecting the other of said pair of contacts with another of said prongs.

4. A fluorescent lamp socket comprising a base and a plug separable from said base, contacts in said base and entrances leading to said contacts, prongs on said plug and insertable through said entrances into engagement with said contacts, a

pair of contacts on said plug for detachable engagement with the contact pins on the end of a fluorescent lamp, means mounted on said plug including a Wire and a heater coil connecting one of said pair of contacts with one of said prongs, and means within said plug and including a wire and a thermally operable starter switch located to be influenced by said heater coil and electrically connecting the other of said pair of contacts with another of said prongs.

5. A fluorescent lamp socket comprising a base and a plug separable from said base, contacts in said base and entrances leading to said contacts, prongs on said plug and insertable through said entrances into engagement with said contacts, a pair of contacts on said plug for detachable engagement with the contact pins on the end of a fluorescent lamp, means mounted on said plug and including a heater coil connecting one of said pair of contacts with one of said prongs, means including a thermally operable starter switch mounted on said plug and located to be influenced by said heater coil and electrically connecting the other of said pair of contacts with another of said prongs, said thermally operable starter switch comprising a substantially U-shaped bimetallic element, said heater coil located between the arms of said element, a contact on one of the arms of said element, a member, a contact on said member and located to be engaged by the contact on said arm, and said member of bimetal whereby to keep its contact in engagement with that of said arm under various conditions of ambient temperature.

6. A fluorescent lamp socket comprising a base and a plug separable from said base, said plug comprising a body, a pair of prongs on said body, a pair of contacts on said body and adapted to be engaged by the contact pins on the end of a fluorescent lamp, means mounted on said body including a heater coil connecting one of said pair of contacts with one of said prongs, means mounted on said body including a thermal switch connecting the other of said pair of contacts with another of said prongs, and said switch located to be influenced by said heater coil and constructed and arranged to open and thereafter stay open on predetermined heating of said coil.

7. A fluorescent lamp socket comprising a base and a plug separable from said base, said plug comprising a body, a pair of prongs on said body, a pair of contacts on said body and adapted to be engaged by the contact pins on the end of a fluorescent lamp, means including a heater coil on saidfilug and connecting one of said pair of contacts with one of said prongs, means including a thermal switch on said plug and connecting the other contact of said pair with the other prong, said switch comprising an arm and a bimetallic element, said element having one of its end portions anchored and having its other end portion partly bent about said heater coil, the free end of the last mentioned end portion of said element comprising a hook adapted to be disposed over the free end of said arm. in electrical contact therewith, and said arm comprising a spring arm whereby on movement of said element due to heating by said coil the arm springs out of position and away from the element to open circuit relation therewith.

8. A fluorescent lamp socket comprising a base and a plug separable from said base, said plug comprising a body, a pair of prongs on said body, a pair of contacts on said bod and adapted to be engaged by the contact pins on the end of a t3 fluorescent lam-p, means includingga heater coil 011* said plug and connectingone of said pair of contacts-with one of said prongs; means including-athermal switch on-said plug and connecting the other contact of said' pair-'- with-the-other prong, said switch I comprising-- an-armand a bimetallic' element, said element having one of its end' portions anchored and-having its other: end portion partly bent about said heater coil, the free--end of the last' mentionedend-portionof said-element comprisinga hook adapted to -be dis-posed over the -free end of said arm in electrical contact therewithwandsaid arm comprising a? spring arm whereby on movement of said element due to heating by said coilthe-annsprings engagedbyrthe contact pins on the end of'afluorescent' lamp, means mounted-on said body including awire and a heater coil connecting one ot said' pair ofcontacts-With one of saidprongs, means mounted on Saidbody including a-wire'and at-ethermals'witch locatedto'beinfluencedb said heater-coil and connectinggtliepther of said pair of contacts with another of said prongs; an d said switch1-constructed and" arranged to openand thereafterstay open on predetermined heating .of said coil."-

10': In a base-for asepa-rabletwo part fluores centlampsocket; said base comprising aybody offinsulating-material 'ha-ving 'apair of chambers therein'and narrow elongated-entrance slots leadingto the respectivech-amb'ers; contactsin the respectivechambers and each; comprising a spring arm "includingbent portion inclming inwardly: of said body and" lying partly across *the entrance slot to-its chamber; from the narrow edge 20f said slot;- each of "said spring arms a'lso including a j portion extending from the i-inn'er-end ofjthe" first?mentioned-portion" and inclining-inwardly of the body and away from the-entrance slot to its 'chamber but at a greater angle tothe planezof the" entrance slot-than the angle-of the first mentioned-portion to'such plane whereby flat' contact prongs havingnotcl'ies in their edges to'receive' the junctures ofthearm portions-may more easil cam. asideztheiarmsyas such prongs enter. the chambers and; engage the first men tioned inclining arm portions than as the prongs are withdrawn from engagement'with the inner surfaces of the second mentioned inclining arm portions.

11. A fluorescent lamp socket comprising a pair of separable parts, a pair of contacts on one of said parts and adapted to be detachably engaged by the contact pins on the end of a fluorescent lamp, means mounted on said body to connect said pair of contacts in a fluorescent lamp circuit when said pair of socket parts are connected, said means including a heating coil in circuit with one of the contacts of said pair and a thermal switch in circuit with the other contact of said pair and located to be influenced by said heating coil. and said switch constructed and arranged to open and stay open on predetermined heating by said coil. 1

12. A fluorescent lamp socket comprising a pair of separable parts, a pair of contacts on one of -said' parts and adaptedito be detachablyen:-. gaged-by the contact-pins. on the end of; a fluoirescent lamp, means mounted. ona said; body; to connect said pair of contacts: in a fluorescent lizmpcircuitswhen said. pair of a socket: parts; are connected, said meanstincluding: a.- heating-icoil in circuit-with one of thezcontacts of said pair and a thermally operable; starter switch". in; circuit with the othencontact ofv saidl pair and located tobe influenced: by said heating coil; and. said starter switch constructed: and arranged. to open on predetermined heating of said coil: and to automatically close on cooling. followingiisuch opening-.

13:2 Aifluorescent lamp socketzcomprisinga pair oftseparableparts, a pair of contactscon one of said parts'and-adapted to be-deta'chably engaged bythecontact pins on the endx-ofa: fluorescent lamp; means"v mounted on said partlito connect said pain of contacts in a fluorescent lamp circuitwhen said pain'ofiparts are connected, said means including a heater: in circuit with onesof said contacts x and: a thermally. operable starter switch 1 in circuit with the other. of: said contacts, said starter' switch comprising a". substantially U-shaped bimetallic element? straddling said heater, a contact-on anarm ofsaid element; a member; a contact on 'saidmember and locatedzto beengaged' by:the-contact on said arm, and said member of-"b'imeta'l whereby to keep its-contact" in engagement with that of-said arm under various conditions of ambient temperature;

14; A fluorescent lampsocket 'comprising a pair of separable partsy a pair of" contacts on one of said part's'and adapted to be detachably engaged b'y'thecontact pins on the end -of a -fl'uorescent lamp; means mounted on said one'ofsaid parts-to connect said pair of contacts in-a fluorescent lamp circuit when said socket parts are connected, said means including a heating coil incircuit with one of.the=contacts ofsaid'pair and a thermally operable starter *switch in circuit withthe other contact of'said' pair, said starterswitch compris ing abimetallic' element 'located to b'e influenced b-y'said heating coil,- a-cont'act on saidelement, a member including a strip anchored at one end andat its other end carrying a contact positioned'to'be-engagedby the contact of theelement asthe'latter-cools, and said strip ofbimetal wherebyto-keep its'contact in engagement with that of said el'ement under various conditions of ambienttemperaturer 15. A fluorescent lamp socket comprising a-pair ofseparabl'e-parts; a pair-ofcontacts'onone of said parts and adapted' to be detachably engaged bythe contactpins on the end of a-fluorescent lamp; means mounted on saidone-of said parts to connect said pair of contacts in a fluorescent lamp circuit when said pair of socket parts are connected, said means including a heater in circuit with one of said contacts of the pair and a thermally operable starter switch in circuit with the other contact of said pair, said starter switch comprising a bimetallic element located to be influenced by said heater, a contact on said element, a member including a strip anchored at one end and at its other end carrying a contact positioned to be engaged by the contact of the element, said member positioned to have its contact engaged by the contact of the element as the latter cools, and said member stiff to keep its contact in engagement with that of the element on initial heating of the latter by said heater.

16. A plug for a fluorescent lamp socket including a base and a plug, said plug comprising a substantially flat body of insulating material, contacts on the outside of said body, said body having entrances from its inner side for the insertion of the end terminals of a fluorescent lamp into engagement with said contacts, a pair of prongs secured against the outer side of the body and projecting beyond one edge thereof, a heater at the outer side of the body and mounted thereon and connected with one of said contacts and one of said prongs, a thermally operable switch on the outer side of the body and connected with the other of said contacts and the other of said prongs, said switch located to be influenced by said heater, a hollow cover on the outer side of said body and enclosing said contacts, heater,

switch and portions of said prongs, and means removably securing said cover to said body.

17. A plug for a separable fluorescent lamp socket including a base and a plug, said plug comprising a substantially flat body of insulating ma- 'terial, contacts on the outer side of said body, said body having entrances from its inner side for the insertion of the end terminals of a fluorescent lamp into engagement with said contacts, a pair of prongs secured against the outer side of said body and projecting beyond one edge thereof, a heater on the outer side of said body and connected with one of said contacts and one of said prongs, a thermally operable switch on the outer side of the body and connected with the other of said contacts and the other of said prongs, said switch located to be influenced by said heater,

a hollow cover on the outer side of said body and enclosing said contacts, switch, heater and portions of said prongs, means removably securing said cover to said body, and a push button mounted by said cover and operable from the outer side thereof to close said switch.

18. In a plug for a separable two part fluorescent lamp socket, said plug comprising a substantially flat body of insulating material, a pair of contact prongs secured against the outer side of said body and extending beyond an edge thereof, a pair of contacts on said side of the body and electrically connected with the respective prongs, said body having openings therethrough for the insertion of the end terminals of a fluorescent lamp from the inner side of the body into engagement with said contacts, a hollow cover over the outer side of said body and enclosing said contacts and portions of said prongs, and means removably securing said cover to said body. 19. A two part socket for a fluorescent lamp,

said socket including a base portion and a plug portion, contacts in said base portion, said base portion having entrances leading to said contacts, contact prongs on said plug portion and adapted to be inserted through said entrances into engagement with said contacts, a pair of contacts in said plug portion in spaced relation to said prongs, said plug portion having entrances leading to said contacts and providing for the insertion of the terminal contact pins into said plug portion in engagement with the contacts therein, a starter switch in said plug portion and including contacts movable to and from engagement and connected respectively with one of said plug contacts and one of said prongs and a heater element associated with and adapted to influence movement of said contact and connected with the other of said plug contacts and the other of said prongs.

EDWIN G. GAYNOR.

HAROLD K. ANDREWS.

CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 399,326 Griggs Mar. 12, 1889 633,039 Read Sept. 12, 1899 957,261 Sargent May 10, 1910 977,836 Platt Dec. 6, 1910 1,568,156 Herskovitz Jan, 5, 1926 1,615,302 Hartmann Jan. 25, 1927 1,681,437 Schweiker Aug. 21, 1928 1,802,230 Aletter Apr. 21, 1931 1,812,343 Johnson et al June 30, 1931 2,023,004 Clayton Dec. 3, 1935 2,160,786 Peterson May 30, 1939 2,170,359 Wirth Aug. 22, 1939 2,236,697 Peters Apr. 1, 1941 2,248,605 Buckley July 8, 1941 2,259,915 Weritz Oct. 21, 1941 2,268,152 Jones Dec. 30, 1941 2,268,522 Abbott Dec. 30, 1941 2,276,829 De Reamer Mar. 17, 1942 2,293,897 Gref Aug. 25, 1942 2,298,336 Babb Oct. 13, 1942 2,298,824 Darley Oct. 13, 1942 2,299,499 Sanford Oct. 20, 1942 2,305,583 Hodgkins Dec. 15, 1942 2,320,424 Gates June 1, 1943 2,321,851 Pope June 15, 1943 2,332,492 Bensin Dec. 19, 1943 2,341,905 Cook Feb. 15, 1944 2,351,440 McCarthy June 13, 1944 FOREIGN PATENTS Number Country Date 250,039 Italy Sept. 4, 1926 

